1. Field of the Invention
This invention relates to surveillance systems. Specifically, the invention relates to a video-based surveillance system that uses an omni-directional camera as a primary sensor. Additional sensors, such as pan-tilt-zoom cameras (PTZ cameras), may be applied in the system for increased performance.
2. Related Art
Some state-of-the-art intelligent video surveillance (IVS) systems can perform content analysis on frames generated by surveillance cameras. Based on user-defined rules or policies, IVS systems can automatically detect potential threats by detecting, tracking and analyzing the targets in the scene. One significant constraint of the system is the limited field-of-view (FOV) of a traditional perspective camera. A number of cameras can be employed in the system to obtain a wider FOV. However increasing the number of cameras increases the complexity and cost of system. Additionally, increasing the number of cameras also increases the complexity of the video processing since targets need to be tracked from camera to camera.
An IVS system with a wide field of view has many potential applications. For example, there is a need to protect a vessel when in-port. The vessel's sea-scanning radar provides a clear picture of all other vessels and objects in the vessel's vicinity when the vessel in underway. This continuously updated picture is the primary source of situation awareness for the watch officer. In port, however, the radar is less useful due to the large amount of clutter in a busy port facility. Furthermore, it may be undesirable or not permissible to use active radar in certain ports. This is problematic because naval vessels are most vulnerable to attack, such as a terrorist attack, when the vessel is in port.
Thus, there is a need for a system with substantially 360° coverage, automatic target detection, tracking and classification and real-time alert generation. Such a system would significantly improve the security of the vessel and may be used in many other applications.